Hydraulic control valve



Oct. 12, 1943. NICHOLS, JR 2,331,790

HYDRAULIC CONTROL VALVE Filed Feb. 25, 1941 3 Shets-Sheet l W I v ATTORNEY5 6 Oct. 12; 1943.

H. L. NICHOLS, JR 7 HYDRAULIC CONTROL VALVE Filed Feb, 25, 1941 3 Sheets-Sheet 2 I I i 20 x y Z 6 INVENTQR )[erber .L. JVZehoZS Jr 44,- BY 9 a: m M f ATTORNEYS Patented Oct 12, 1943 UNITED STATES PATENT OFF l CE 2,331,790 RAULIC CONTROL vanvs Herbert L. Nichols, Jn. Greenwich, Donn. Application February 25, 1941, Serial No. 330,509

9 Claims.

This invention relates to valves and more particularly to a valve of the serted in a. fluid power passage of the fluid.

A further object is to provide a. valve which by the action of a single control lever may control the flow of fiuid in several different courses and at difierent pressures at the same time.

My valve is particularly adapted for use with a series of pumps and cylinders containing pistons and while I have illustrated a particular use it will be understood that the principles of the valve may be adapted to many similar devices in which fluid power is used.

More particularly, an object of this invention is to provide a valve adapted to be used with a type-adapted to be incircuit to control the plurality of cylinders having pistons to control the passage of fluid through pipes leading to said cylinders above and below said pistons and adapted to actuate said pistons.

My invention is so constructed and actuated that an operator of a, valve embodying the invention may, by the use of a single operating handle, selectively control the flow of fluid through the various pipes and cause the fluid to flow through various combinations of said pipes and to impede the flow-through other pipes to move said pistons in the manner desired.

In the drawings I have shown my invention embodied in a valve adapted to control two pistons which, in turn, position the blade of a bulldozer. by adding additional sections to the core of the valve it will be possible to control additional pistons and to selectively operate one or more of said pistons alone or in combination with others to produce the desired result. In the present embodiment four pipes only are involved and since in this embodiment the movement of one piston involves the movement of the other, a combination is provided controlling the passage of fluid to two of the four pipes at the same time, although the particular two pipes involved may be combinations of any two of the four pipes. In other words, fluid may be forced through the pipes to the tops of both cylinders at equal or difierent pressures in one combination, into the bottom of bothcylinders' in another combination, into the top of one and the bottom of another, or vice versa, and pressure may be forced into either end of either cylinder, and the exhaust from the opposite end'of the other cylinder impeded as much or as little as may be desired.

In the accompanying drawings- It will be appreciated, however, that,

- of the valve and controls;

Fig. 3 is an end elevation of the valve and control structure;

. into and from one or Fig. 4 is a diagram employed;

Figs. 5, 6, 7, 8, 9 and 10 are vertical'cross sections taken on the lines 5-5, t6, 7-7, 8-8, 99 and ill-l5, respectively, of Fig. 2;

Fig. 11 is a development of the outside of the valve core flattened out;

Fig. 12 is a development of the inside of the valve case flattened out;

Fig. 13 is a top plan view ofthe valve;

Fig. 1 is a vertical cross section of the lower valve shown in Fig. 13 on an enlarged scale;

Fig. 15 is a plan view of the cam or block forming part of the valve shown in Fig. M;

Fig. 16 is a plan view of the actuating mechanism cooperating with the cam shown in Fig. 15;

Fig. 17 is a cross section of a view of the valve similar to Fig. 2 but showing a modified form of my invention;

Figs. 18, 19, 20 and 21 are vertical cross sec tions taken along the lines it-ie, some, Eb-fiii of the hydraulic system and 2I-2i, respectively, of Fig. 17.

As will become apparent, one of the purposes of my invention is to control the passage of fluid more of a number of se lected channels. Cne application to which my valve may be put is illustrated in Fig. i where a conventional tractor or bulldozer is shown. This device is provided with a frame one each side thereof to which frame is pivotally mounted a scraper 2?. In the operation of the scraper it is advantageous to be able to raise and lower the same and also to vary the angle of the scraper. This may be done by raising one side and lowering the other, or by merely lowering or raising one side. The position of the scraper 21 is controlled bythe operation of two shafts 28 and 29. These shafts are connected with the frame 2% and have on their opposite ends pistons 3b and 3!, respectively, enclosed in cylinders 32 and 33. It will be appreciated that by the operation of the pistons within the cylinders the height and angle of the scraper 2'! may be varied.

Referring more particularly to Fig. 4, the system includes a tank from which the pipe 36' leads to a pump designated as pump A and pipe 31 leads to a pump designated as pump B. Pumps A and B supply equal pressure through the pipes 38'and 39, respectively to a valve 40. From the valve 4|], pipe 4| leads to the cylinder 32 above the piston, while pipe 42 leads from the valve to the cylinder 32 below the piston. Similarly from the valve, pipe .43 leads to the cylinder 33 above the piston, while pipe 44 leads from the valve to the same cylinder below the piston. It will be seen that the purpose of the valve 40 is to control the flow of fluid selectively through the pipes 4|, 42, 43 and 44 and so operate the pistons 36 and 3| as to place the scraper 21 in the desired position. The passage of fluid through the pipes 4| and 3 int the cylinders 32 and 33 will force the pistons downwardly and thus tend to lower the scraper. The passage of fluid through the pipes 42 and 44 will cause the pistons to move upwardly to lift the frames 26 and scraper 21 connected. therewith. It will be likewise apparent that the passage of fluid through the pipe 43 and through the pipe 42 will cause the piston 3| 'to move downwardly and the piston 30 to move upwardly to lower the right hand frame 26 and raise the left hand frame 26 to lower the scraper on one side and raise it on the other, and the reverse position of the scraper will. be secured by the passage of fluid through the pipes 4| and 44. In addition to the pipes heretofore described, a return pipe or by-pass 45 runs from the valve back into the tank.

The valve 40 consists essentially of a case 50 and a hollow core The core 5| is divided into chamber by partitions 52, 53 and 54 perpendicular to the longitudinal axis of the case. These chambers are provided with a multiplicity of ports through their outer curved surfaces. The case 50 has ports cut in its inner surface which are inward extensions of lateral passages or external pipe connections. The core 5| may be tapered slightly for adjustment purposes and it will be seen that the end 55 thereof engages a nut or collar 56 for adjustment. The opposite end of the core, 51, is fastened to a rod 58 which passes through the case and a packing gland 59. In the bifurcated end 60 of the rod 58 is pivoted the control lever Bl so that if the operating lever is moved to either sid it will rotate the core 5|, although it may be swung away from or toward the valve without rotating the core. As will hereinafter be explained, the rotation of the core governs the up-and-down motion of the blade while the movement of the operating member toward or away from the valve governs the tilt of the scraper or blade. A guide arc 52 is hingedly mounted in brackets 53 and 66, said brackets being on the same plane with the end 60 of rod 58, so that the guide are may swing with the operating handle 53 without changing its relative position thereto. The operating nandle 5| is provided with a bracket. 65 carrying a shoe 55. The bracket 55 engages the upper portion iii of the guide are 52 and the shoe is adapted to engage, under presizure of the spring 68, depressions Bil in the guide arc 62.

As has been previously pointed out, the pipe ll leads to the top of the right cylinder 32, pipe 42 to the bottom of the sam cylinder, pipe to the top of the left cylinder, and pipe a l to the bottom thereof. -The purpose of the valve is, therefore, to control the passage of oil through the respective pipes to operate the pistons in the cylinders and thus control the position of the blade.

top of the right cylinder and the section shown in Fig. 7 controls the flow of oil through the pipe 44 to the bottom of the left cylinder. In Fig. 9 the section controls the flow through pipe 42 to the bottom of the right cylinder, while in Fig. 10 the section controls the flow through pipe 43 to the top of the left cylinder. It will be noted that above the sections. shown in Figs. 6 and 7, is a common chamber H from which the pipe 39 extends to pump B. These sections are also supplied with an exhaust chamber 12 which connects with the pipe 45 returning to the tank. Connecting the chamber H and the exhaust chamber 12 is a passage 13. The sections shown in Figs. 9 and 10 are likewise connected with a common chamber 15, which is connected to the exhaust chamber 'i2 by a passage I6. The pipe 38 in pump A leads to chamber 15.

Extending laterally throughout the valve case are lateral passages 80 and BI, which at the handle end of the valve are connectedby passages 82 and 83 which lead to the exhaust chamber 12. The passage 82 is normally closed by a tilt valve 85 and the passage 83 is normally closed by a tilt valve 86. These valves are substantially identical and a detail view thereof will be found in Fig. 14.

The valves 85 and 86 consist of cups 8'! which rest against the seats 88 by action of a valve Referring to Figs. 6 to 10,11; will be seen that Fig. 6 shows the portion of the core which controls the flow of oil through the pipe ll to the 95 on a cam disk spring 89. They are provided with adjusting rods 90 and have at the top of the rods a block 9| secured against rotation by pins 92 fixed in a plate 93. The blocks 9| are provided with widened groove 94 on their upper surfaces. These grooves 94 are adapted to accommodate the bead 95 to which is pivoted at 91 an arm 98 in the valv 85 and a similar arm I04 in the valve 86.

Bivotally attached to the guide are 62 at I00 is an arm |0| which is, in turn, pivoted to a rod I02. To the rod |02 there is pivoted the arm 98 at E03 and the arm I04 at I05. It will be seen that the movement of the operating handle 6| toward or away from the valve will carry with it the guide are 62 and will either pull or push the rod I02, thus moving the arms 98 and I04 and rotating the cam disks on the valves 85 and 80. The valves 85 and 86 are constructed and set to open on a very slight pressure when the head 95 is resting in the groove 94. The action of the bead on the cam disks in the groove in the block is such that if the cam disks are rotated in a clockwise direction the head 95 will attempt to climb out of the groove 94, thus exerting pressure on the cup 81 of the valve. If the cam disks are rotated in a counterclockwise direction the bead can rotate in the widened section of the groove without exerting any pressure against the block. It will be seen, therefore, that if the operating handle BI and the guide are 52 are moved away from the valve, the cam disk on the valve 85 will be rotated in a clockwise direction while the cam disk on the valve 85 will be rotated in a counterclockwise direction This will tend to put additional pressure on the valve 86 while the valve 85 will be free from additional pressure. In the same manner, the opposite movement of the operating handle 6 I, that is, toward the valve, will rotate the cam disk on the valve 55 in a counterclockwise direction and the cam disk on the valve 85 in a clockwise direction, exerting additional pressure on the valve 35 while not affecting the valve 80. The valves 85 and 85 have a maximum setting which is substantially less than the pressure developed being no through the port A and from by the pumps A, and B so that even though the valves are set under pressure, back pressures may be lay-passed therethrough if sufficient pressure is built up.

It will be appreciated that the operating handle shown in Figs. 2 and 3 and the cores illustrated in Figs. 6, 7, 8 and 9 are shown in the hold position with the openings W, Y, Z and'X to the pipes M, :32, it and d6 closed. This will lock the oil in the pipes and cylinders and prevent movement of the pistons. In this position the ports A and E are open to chamber It and the ports H and M to chamber is. The ports D and M communicate with the lateral passage so and the ports'E and 'I communicate with the lateral passage 85, so that oil coming from both pumps and entering the ports A, E, H and M may pass through the ports D and M and E and I into the passages to and 8!, through the valves 85 and 86 into the exhaust chamber 72 and through the pipe 35 back to the tank.

If the operating handle is moved all the way to the right, the core is turned and a float position is secured in which the openings W, X, Y and Z to the pipes il, dd, 32 and as coincide with the ports B, F, J and 0, respectively. Oil may pass into the core through the port A from the chamber chamber l5, and it may by-pass through the port P to the pipe iii? and through the port E to the pipe 35. In the float position, therebeing no pressure exerted in either of the cylinders 32 or 33, the blade will rest by its own weight on the ground.

If the handle is moved all the way to the left, another float position is secured in which the openings W, X, Y and Z to thepipes 36, M, (2 and coincide with the ports C, G, K and P, respectively, and fluid may pass from the chamber ii through the port E and from the chamber '55 through the ports'I-I and N. Fluid may also pass to the pipe 88 through the port M and into the pipe 85 from ports F and B. If the handle is moved only part way to the left, the core is rotated to the up position in which the openings W, X, Y and Z to the pipes fill, Alt, lfl and 43 coincide with the ports C, G, K and P, respectively. Fluid may enter the two central sections of the core through the ports H and E and may pass from the exterior sections of the core into the pipe 8Q through the port M and into the pipe 85 through the port B; In this position, there pressure on the valves t and 86, fluid from pipes ill and 63 can exhaust freely and all pressure will be exerted through the pipes M and to the bottom of each cylinder 32 and 33 to raise the blade. If the handle is moved half way to the right, oil may flow from chamber H chamber it through the port li I into the exterior sections of the core, while the openings W, X, Y and Z to the pipes =35, 3:3, 52 and 63 will coincide with the ports B, F, J and O. The port E will be open to the passage iii, while port L will be open to passage as in the central sections of the core so that fluid in the sections will be by-passed back to the return pipe. This position will force all the fluid through the pipes at and 83, entering the cylinders 32 and 33 above the pistons and thus forcing the pistons downwardly, the displaced fluid flowing through pipes 62 and id to exhaust passages.

Attached to the rod I02 is a sliding member till forming a gate valve between the passages 73 and H and IE and 75. The sliding member ii and through the port M from the 3 H0 is provided with an opening I l I so positioned that when the operating handle 6| and the guide are 62 are moved away from the valve, the opening-lll will connect the passage 13 with the chamber II, while when the operating handle and the guide arc are moved toward the valve the opening I M will coincide with and connect the passage 16 with the chamber I5, but when the handle is centrally positioned, both will be closed. It will be seen, therefore, that when the operating handle 6i and the guide are 62 are moved away from the valve, the passageway 73 will be opened and fluid coming from pump B will be free to pass through the pipe 39 into the chamber H, through the passage 13 into the chamber 12 and out through the return pipe 65, back into the tank 35. Oil or fluid coming from pump A. will not be by-passed since the sliding member Ht will close the passage 16. At the same time, the movement of the handle being away from the valve, a clockwise rotation of the cam disk on the valve 86 will take place, thus exerting additional pressure on the valve 86 which will require considerable pressure to open, so that pressure will build up in passage as. It will be seen that by allowing the pressure to by-pass out of the chamber H through the passage it into the exhaust chamber 72, the pipes 38 and at will be robbed of their pressure, while the pipes 32 and 48 will continue to receive pressure from the pump A if the core should be so positioned.

This tilting operation may not be executed in the hold position when all the openings W, X, Y and Z leading to the pipes 41,. 4d, 32 and #33 are closed.

If the handle is in the left float position, oil returning through the pipes M and it passes through the ports B and F into the pipe 8!, through the valve 85 into the chamber H and theexhaust pipe 85. While the port M will, at the same time, register with the pipe 80, it will be appreciated that pressure on the valve 86 will prevent the oil from being by-passed into the exhaust chamber, so a pressure depending on 86 will be supplied to pipes 42 and 33.

If the handle is in the other float position,

that is, all the way to the right, oil returning through the pipes ti and 4 3 will pass through the port E into the passage BI and back to the tank, while the port P will register with the pipe and pressure on the valve 86 will hinder oil in being by-passed therethrough. It will readily be understood that by moving the operating handle El toward'the valve, passage 76 will be opened while passage 73 will be closed. The oil will be forced through the pipes 6i and 44, while the oil in the section of the core farthest from the handle 69 will be allowed to 'by-pass through the passage it into the exhaust passage 12. The valve 855 will receive additional pressure since its cam disk will be rotated in a clockwise direction and resistance will, therefore, be ofiered to oil attempting to by-pass through the passage 8! while oil will be free to by-pass through the passage tll.

It will be appreciated that while the foregoing description has dealt with various movements of the blade,'only a single action was involved in each, that is, the raising and lowering of' the blade or tilting. it from one side or the other,

and to simultaneously cause it to tilt with one end higher than the other. By placing the operating handle in the up position, fluid will be formed through the two central sections of the core to the bottoms of the cylinders, and, the tops of the cylinders will be exhausted, as previously described. Now, if the operating handle is moved toward the valve, the pressure from pump A will be by-passed through chamber 15 and the gate valve port Hi to exhaust passage 12, causing a cessation of the pressure which would otherwise by delivered from 15 through ports H, K and Y and pipe 42 to the bottom of cylinder 32. At the same time, the clockwise movement of bead 95 in groove 94 will increase the tension on' tilt valve 85, impeding the escape of fluid from the top of cylinder 32 through pipe 4I, ports W, C and B and passage 8!, said impediment becoming greater as the operating handle is moved further from the perpendicular. The top of cylinder 33 will continue to exhaust unimpeded through pipe 13, P and M and passage 80. The result of these various actions is that the scraper-blade is pushed up on the side of cylinder 33 and is impeded in its upward movement by a lesser back pressure or resistance in the top of cylinder 32. The piston in cylinder 33 will, therefore, rise until the torsion of the blade, twisted in this manner, is sufficient to create enough pressure in the top of cylinder 32, and so in passage 8i to displace the tilt valve 85 from its seat. The blade will then rise in this tilted position.

If the operating lever is kept inclined toward the valve, and is rotated into the down position, pump B will now exert pressure on the top of cylinder 32, through passage TI, ports A, B and W and pipe 4|. Pump A is still by-passed as described above. The exhaust from the bottom of cylinder 33 through pipe 44, ports X, F and E and passage BI is obstructed by the tilt valve 85. The efiect of this downward pressure diagonally opposed bya lesser resistance will again be to cause the blade to twist until the tilt valve 85 is opened, after which the blade will descend in this tilted position. It will be noted that the amount of tilt in each case is determined by the rigidity of the 'scraper tending to keep it level, and the resistance of the 'tilt valvetending to twist it. Since the rigidity of the scraper is a constant; the amount of tilt is directly dependent on the degree that the operating lever is moved out of the perpendicular. It will be noted that if this inclination is kept constant, the lever can be rotated from up to down positions without changing the tilt. In the hold position the closing of the cylinder ports will lock the blade in any tilted position.

If it were desired to tilt the blade oppositely, the operating handle could be moved away from the valve, with the result that the pressure of pump B would be by-passed through chamber II, port HI, passages 13 and i2 and pipe 45. In the up position pressure would be delivered only to the bottom of cylinder 32, through chamber 15,.ports H, K and Y and pipe 42. The top of this cylinder would exhaust through pipe 41, ports W, C and B into passage 8|, past tilt valve 85, which is released in this position of the operating lever through passages 82 and 12 to pipe 45. The top of cylinder 33, however, exhausting through pipe 43, ports Z, P and M into passage 80, will encounter the resistance of tilt valve 86 now subjected to compression by the clockwise when M its am member. The bottom of 528 is pivotally cylinder 33 is released through pipe 44, portsx,

G and E, chamber ll, passages 13 and 12 and pipe 45. We therefore have again the situation of an upward pressure diagonally opposed by a lesser resistance. The scraper blade will therefore twist with the end governed by cylinder. 32 higher, and in this twisted or tilted position will rise.

Now if the operating lever, while still positioned away from the valve, is rotated into the down position, pressure will be supplied to the top of cylinder 33 from pump A through passage 15, ports M, O' and Z and pipe 43. The bottom of this cylinder would be released through pipe 44, ports X, F and E and passages BI, 82 and 12, :ivhile the exhaust of the bottom of cylinder 32 through pipe 42, ports Y, J and L into passage is impeded by tilt valve 86, so that resistance :is set up to the downward movement of the blade, causing it to twist. The top of cylinder 32 can draw fluid from chamber H, through ports A, B and W, and pipe 4|, to fill any vacuum created by the upward movement.

The pressure system of each pump may be provided with a relief valve to by-pass undue pressures or to equalize the system. These valves may be mounted on the pumps, in the lines, or on the inlets to the rotary valves, but since they are conventional in design they form no part of this invention and they have not been illustrated.

In the modification shown in Figs. 17 to 21, inclusive, the structure is'substantially identical except that relief valves i253 and Hit are'each positioned horizontally at the top of the case 56 with their adjusting rods W2 and M3 pointed toward each other. The ends of these rods are threaded-into rounded ends i2 3 and M? which are pressed by the springs against the central cam member i28 which is rotatably mounted on a pin i2? and fastened to a rod 123. The rod fastened to the arm Hi2. It is intended that these relief valves ed and adjusted that when the operating lever is set they will open at equal pressures, substantially lower than the pumps are capable of developing, and that the, by-passed fluid will be returned to the tank through passage 12 and pipe 45. It will therefore be seen that the eifective working pressures in chambers II and I5 depend on the position of the cam I26, which in turn is dependent on the position of the guide arc 62 and the operating lever. If the control member is moved toward the valve the cam member i26 will be caused to rotate on thepin I21 so as to increase the tension of the spring in the valve i211 by pushing against the rod I22 and will release the adjusting rod of valve l2| somewhat, so that oil from the chamber 15 may more readily by-pass through the valve I2l. With this structure it will be seen that the further the operating handle is pushed toward the valve the greater will be the pressure exerted on the valve H20 and the less on the valve I2l.

As an example of operation of this modification, if it is desired to raise the scraper with the side controlled by cylinder 33 higher, the operating lever will be rotated into the up position and inclined toward the valve. This inclination will cause tilt valve 85 to impede exhaust from passage 8|, as previously described. It will also reduce the pressure of valve l2i against its seat, allowing fluid more readily to escape past it into passage 12, thus reducing the pressure in chamber 15, while it will increase the pressure of be so constructassured valve I26 sure in Now the high pressure from chamber H may go through ports E, G and bottom of cylinder 33, while the lesser pressure from chamber will be transmitted through ports H, K and Y and pipe 42 to the bottom of cylinder 82. This lesserpressure will be opposed by the passage of fluid from the top of cylinder 32 through pipe M, ports W, C and B and passage til being impeded by the tilt valve 8, while the top ofcylinder 33 can freely exhaust through pipe it, ports Z, P and M and pwsages 8, 83 and 12. The result of this will clearly be that the blade will rise with the side controlled by cylinder Elli high. Other actions of raising, lowering and tilting the scraper will follow the pattern outlined for the basic form of the valve.

In this modification, stead of one pump being entirely by=passed by sldeward motion of the operating lever and guide arc, the pressure from it is reduced, while the available pressure from the other pump is increased. The efieot on tilting and movement, of the blade is the same, but the transition from level to tilted operation is smoother, and operation in a tilted position is steadier and more powerful.

It will be noted that in either of the forms herein described the operator is in complete control of the up-and-down motion of the blade by moving the operating lever El from left to right against its seat. increasing the preschamber H.

on the are 532 and that the supply from the twopumps will tend to keep the blade more positively level than with the tern. In addition, by moving the same control lever toward or away from the valve the operator has complete control of the tilt of the blade and yet retains his ability to'move it up or down while in the tilted position. The result of these advances is not only the elimination of the troublesome Job of mechanically changing the tilt of the blade for difierent types of work, but enables a machine so equipped to operate in boulder-infested terrain, on side hills, near walls, and in materials of uneven resistance with a flexibility and steadiness not heretofore possible with this type of machinery. It also makes possible the construction of new types of trail-builder frames in which the resistance to torsion can be left to hydraulic control.

I claim:

1. In a hydraulic control valve adapted to selectively control the passage of oil to any two of four outlets, a casing, a core in said casing, a supply passage in said casing at the top thereof, an exhaust passage laterally extending through said casing, a series of outlet passages each communicating with one of said four outlets, lateral passages on either side of said casing, a passage communicating with each of said lateral passages and with said exhaust passage, valves controlling each of said lateral passages, ports in said core adapted to, register with said supply passages, said outlet passages and said lateral passages when said core is rotated, and an operatlng handle for rotating said core and for controlling said valves in said lateral passages.

2. In a valve for a hydraulic system, a casing, a plurality of pipes leading from-said casing, a plurality of pumps each leading to separate chambers in said casing, an exhaust chamber in said casing, an outlet from each of said firstmentioned chambers to said exhaust chamber, a valve controlling said outlet, lateral passages in it will be noted that inusual onepump wssaid casing communicating at one end with said exhaust chamber, valves controlling said lateral 7 said core is rotated said ports will communicate with certain of said chambers and pipes, and a single controihandle for rotating said core and selectively operating each of said aforementioned valves.

3. In a valve for a hydraulic system, a casing, a hollow partitioned core in said casing, ports in said core, an exhaust passage in said casing, lateral passages in said casing communicating at one end with said exhaust passage, valves controlling communication between each of said lateral passages and said exhaust passage, inlet chambers in said casing, each of said inlet chambers communicating witha definite section of said core, a passage communicating with each of said inlet chambers, a valve in said passage, an operating handle for rotating said core to selectively register the ports in the core with said passages and chambers, and means connected with said operating handle for the selective operation of each of said valves.

4. In a device of the character described, a

casing, a hollow partitioned core in said casing,

inlet and outlet ports in said casing, an exhaust passage in said casing, lateral passages in said casing communicating at one end with said ex= haust passage, said core having ports therein complemental to said inlet and outlet ports, on-

haust and lateral passages, valves controlling the communication between said lateral passages and said exhaust passage to impede the return flow of fluid to build up pressure, each of said valves including an operating rod, a block on said operating rod, a groove converging near its middle in said block, a disk having a head in said groove whereby said bead when said dish is rotated in one direction will move within said groove in order not to interfere with its impeding action and when rotated in the other direction will exert pressure upon said block to shut the valve, and means for rotating said disk.

5. In a valve for a hydraulic system, a casing,

a hollow partitioned core in said casing, ports in lateral passages in said casing communicating at one end with said exhaust passage, valves controlling communication between each of said lateral passages and said exhaust passage, inlet chambers in said casing, each of said inlet chamhers communicating with a definite section of said core, a passage communicating with each of said inlet chambers, a valve in said passage, an operating handle for rotating said core to selectively register the ports in the core with said passages and chambers, and means connected with said operating handle for the selective operation of the last-mentioned valve and one of said valves in said lateral passages.

6. In a control valve for use in a liquid pressure system having a pair of cylinders, a casing, flow connections between the opposite ends respectively of each of the cylinders and the interior of said casing, a core having rotary movement in said casing, said casinghaving a series of inlets for the inflow of liquid under pressure therelnto, an outlet for the return flow of liquid therefrom, a series of ports and passages communicating with said inlets and outlet, respectively, said core having a series of ports therein which cooperate with said flow connections, said liquid member to operate said valves in said passages and said core so that ports therein will cooperate with said ports'and passages in the casing upon the manipulation of said control member whereby liquid may flow into one end of both of said cylinders and flow out the other end of said cylinders simultaneously, and vice versa, and also whereby liquid may flow into the upper end of one cylinder and out its lower end while the outflow of from the other cylinder is throttled, to supply pressure to one side of the piston in one cylinder and cause said piston to drag with it the piston in the other cylinder.

7. In a control valve mechanism for use in a liquid pressure system having a pair of cylinders, a casing, flow connections between the opposite ends respectively of each of the cylinders and the interior of said casing, a core member adapted to be rotated in said casing, said casing having a series of inlets for the inflow of liquid under pressure thereinto, an outlet for the return flow of liquid therefrom, a valve member connecting said inlets with said outlet, a series of passages connecting with said outlet, retarding valves in certain of said passages communicating with said outlet, said core having a series of ports therein which cooperate with said flow connections, said inlet ports and said passages in the casing upon the rotation of said core, a single control member connected to rotate said core and actuate said valve member and retarding valves to control the flow of liquid whereby liquid may flow into one end of both of said cylinders and fio w out the other end of said cylinders simultaneously, and vice versa, and also into the upper end of one cylinder and out its lower end while the outflow of liquid from the whereby liquid may now ing a port therein carried other cylinder is throttled, to supply pressure to one side of the piston in one cylinder and cause said piston to drag with it the piston in the other cylinder.

8. In a control mechanismior a liquid pressure system, a casing having a pair of inlet ports, outlet ports and return flow passages, a rotatable hollow partitioned core having ports therein complemental to said inlet and outlet ports and return flow passages, a slidable valve member hayby said casing, and means connected with saidcore and valve member to set them to-form paths for the flow of liquid from either of said inlet ports selected to and out through certain of said outlet ports while also lay-passing liquid from either non-selected inlet port to said return flow passages, said means consisting of a single control element manually operable and connected to the core and valve member respectively so that the control element may be swung laterally in opposite directions to impart rotary movement to the core to set it and also that the control element may be moved to and fro to slide the valve member to set it.

9. Pressure control mechanism including a main valve through which liquid may flow from two inlets to four outlets, said valve having a return flow outlet, a control element mounted for pivotal movement in planes at right angles to each other, said valve being operated by the movement of said element in one plane, a second valve means normally operable to impede the return how of liquid from two of saidoutlets to said return flow outlet, said second valve means being connected with said element to be operated thereby to restrict the return flow when saldelement is moved in its second plane, and-a third valve means operated by said element upon movement of the latter in the secondplane to by-pass liquid from either one or the other of said inlets to said return flow outlet.

I-ERBERT L. NICHOLS, J R. 

